Why is wine used at orgies?

From the times of Bacchus to the mess of Musk.

http://www.ncbi.nlm.nih.gov/pubmed/15939164

 It was found that naturally occurring GHB and GBL were detected in those beverages involving the fermentation of white and particularly red grapes. No GHB or GBL was detected in other drinks such as beer, juice, spirits or liqueurs.